JPH06296907A - Coating material discharge control device in airless coating apparatus - Google Patents

Abstract

PURPOSE:To prevent the overshoot of the discharge of a coating material at the time of changing the set value of a control signal. CONSTITUTION:A controller 11 for outputting an electric control signal to an electropneumatic regulator 9, is continuously variable by turning a rotary switch 13 to set each measure 12, allowing a set value to be changed and also, its set value is gradually changed between measures 12. When the set value of a control signal is increased, the rotary switch 13 is gradually turned toward the measure 12 for a new set value to output a control signal where a control value is gradually changed with an inclination toward the new set value to an electropneumatic regulator 9. Thus the feeding pressure of driving air to an air motor 1 is gradually raised as shown in (a) of the figure (B) to gradually increase the kinetic velocity of the air motor 1. And the liquid pressure of the coating material forcibly fed from pumps 2a, 2b is also gradually increased without exceeding the target value to attain the target value as shown by (b).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airless coating device for controlling the discharge amount by adjusting the pressure of the paint fed from a pump.

[0002]

2. Description of the Related Art First, an outline of a two-liquid type airless coating device will be described with reference to FIG. 1A showing an embodiment of the present invention. Driving air is supplied to an air motor 1 from an air supply source 10. Driven by the main agent pump 2 connected to it
a and the hardener pump 2b are driven to drive the tank 3a,
The main agent A and the curing agent B stored in 3b are respectively pumped up, pressure-fed at a high pressure, mixed by the mixer 4, supplied to the coating gun 5, and then discharged from the nozzle 6.

In such an airless coating apparatus, the discharge amount of the paint is determined by the diameter of the nozzle 6, but even if the nozzle 6 having the same diameter is used, the liquid pressure of the paint is changed to ± 10.
Although it is in the range of%, the discharge amount can be changed.

For that purpose, the supply pressure of the driving air to the air motor 1 for driving the pumps 2a, 2b may be changed,
Therefore, as shown in the figure, an electropneumatic regulator 9 that can change the supply pressure of the drive air in accordance with an input electrical control signal is provided in the drive air supply path 8, and the electropneumatic adjustment is performed. Bowl 9
The discharge amount is partially changed by changing the set value of the control signal to the.

[0005]

Conventionally, when the set value of the control signal to the electropneumatic regulator 9 is changed, a plurality of set values are set in advance and selected and output by a switching switch or the like. Therefore, for example, when the set value is increased, the supply pressure of the driving air to the air motor 1 becomes (a) in FIG.
As shown in (b), the movement speed of the air motor 1 and the supply air pressure are unbalanced, and the movement speed of the air motor 1 becomes temporarily higher than expected. ), The target pressure is exceeded as shown by the position of the arrow x, that is, the discharge amount is temporarily excessive, resulting in uneven coating.

[0006]

A paint discharge amount control device for an airless coating device according to the present invention has been completed in view of the above points, and a paint gun for painting paint at a high pressure by a pump driven by an air motor. In the airless coating device that is designed to pump and discharge the air, an electropneumatic regulator that changes the supply pressure of the drive air in response to the input electrical control signal is installed in the drive air supply path to the air motor. And the setting value of the control signal to the electropneumatic regulator can be changed, and
When the set value is changed, a controller having a function of gradually changing the set value toward the new set value is provided.

[0007]

When the set value of the control signal to the electropneumatic regulator is changed by the controller, the set value of the control signal gradually has a gradient toward the new set value due to the function of the controller itself. Is changed to.

Therefore, the supply pressure of the drive air supplied to the air motor also gradually changes, and accordingly, the air motor gradually changes its height while keeping its movement speed in balance with the air supply pressure. The liquid pressure of the paint pumped from the machine reaches the target value without exceeding the target value, and the target discharge amount of the paint can be obtained without exhibiting an excessive or insufficient state.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. In this embodiment, a controller 11 is connected as a means for inputting a control signal to the electropneumatic regulator 9 in the airless coating device described above.

In this controller 11, a plurality of set values of the control signal are determined corresponding to a target paint discharge amount, and the index 14 of the rotary switch 13 is switched to the scale 12 formed in the order of magnitude of each set value. In addition to being able to change the set value by adjusting them together, the index 14 of the switch 13 is set on each scale 1
While rotating between 5, the set value can be gradually changed, that is, the set value of the control signal can be continuously varied and output.

This embodiment has such a structure, and when the set value of the control signal is increased, the rotary switch 13 is gradually rotated toward the scale 12 having a new set value, and the control signal is changed to the control value. Is gradually output to the electropneumatic regulator 9 while gradually increasing with a gradient toward a new set value.

Therefore, the supply pressure of the driving air supplied to the air motor 1 gradually increases toward the target value as shown in FIG. 1 (B) (a), and the air motor 1 changes its movement speed accordingly. The air pressure is gradually increased while keeping a balance with the supply air pressure, and as a result, as shown in (b) of the figure, the fluid pressure of the paint pumped from the pumps 2a, 2b does not exceed the target value and gradually increases. To reach the target value, and the discharge amount of the paint reaches the target value without causing a temporary excess phenomenon.

Of course, even when the set value of the control signal is lowered in order to lower the paint discharge amount, the paint discharge amount can be lowered to the target value without excessive fluctuation by performing the same operation.

In the above embodiment, the control value of the control signal is changed with a gradient by mechanical means by operating the rotary switch 13. However, electrical control such as a time constant circuit is performed. Alternatively, it may be automatically performed by switching the set value using a means.

Further, the present invention is not limited to the two-liquid type of the above-described embodiment, but can be widely applied to control of the paint discharge amount of the airless painting apparatus in general including the single paint type.

[0016]

As described above, according to the present invention,
When changing the paint discharge amount by changing the control signal value, a stable discharge amount can be obtained without exhibiting the so-called overshoot phenomenon in which the discharge amount exceeds the target value even at the start-up, and there is no uneven coating The effect is that it can be painted.

[Brief description of drawings]

FIG. 1A is a configuration diagram of an embodiment of the present invention,
(B) is an explanatory view showing a state of changes in the air pressure of the driving air and the liquid pressure of the paint.

FIG. 2 is an explanatory diagram showing a state of changes in air pressure and hydraulic pressure according to a conventional example.

[Explanation of symbols]

1: Air motor 2a, 2b: Pump 5: Painting gun
8: Supply path (for driving air) 9: Electropneumatic regulator 11: Controller 13: Rotating switch A: Main agent B: Curing agent

Claims (1)

[Claims] 1. An electric control signal input to a drive air supply path to the air motor of an airless coating device in which a pump is driven by an air motor to pump the paint at a high pressure to discharge the paint. In addition to the electropneumatic regulator for changing the supply pressure of the driving air corresponding to
Provided is a controller capable of changing the set value of the control signal to the electropneumatic regulator, and having a function of gradually changing the set value toward a new set value with a gradient. A paint discharge amount control device in an airless coating device.